Direct current conversion circuit

Abstract

The utility model relates to the technical field of power electronics, and discloses a direct current conversion circuit, which comprises an input filtering module, a communication circuit module, an isolation BOOST module, an output filtering module, a power supply module, an output filtering module, a power supply module, an output filtering module, a power supply module, an output filtering module, a power supply module and an output filtering module, and is characterized in that the communication circuit module is connected with a peripheral control output end and an isolation BOOST module and is used for providing control signals for the isolation BOOST module; the isolation BOOST module comprises two isolation BOOST modules, and the isolation BOOST module comprises two isolation BOOST modules; for one isolation BOOST module, the isolation BOOST module comprises a control module and a power main loop module. The control module controls the operation of the power main loop module according to the control signal; the isolation BOOST module adopts a parallel-in series-out framework, two paths of isolation BOOST modules are arranged in the isolation BOOST module, each path outputs voltage V and power W, the two paths output voltage 2V and power 2W after being connected in series, and the control module and the power main loop module can be independent of each other, so that the power conversion efficiency can be ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a direct current conversion circuit. Background Art

[0002] Direct Current / Direct Current (DC / DC) converters are widely used in remote and data communications, military, computer, aerospace and other fields. DC / DC converters convert fixed DC voltage into variable DC voltage through DC / DC conversion circuits. With the development of science and technology, more and more types of integrated circuits are used in electronic equipment products in the above fields. The power supply voltage required by the integrated circuits is different, and DC / DC conversion circuits are needed to provide DC power for electronic equipment according to demand.

[0003] Most of the DC / DC conversion circuits currently used in DC / DC converters directly connect two DC branches in series. Therefore, the output current in the DC / DC conversion circuit remains unchanged, that is, the output current is the same regardless of whether the output is high-voltage DC or low-voltage DC. When the voltage required by the electronic device is low-voltage DC, the current remains unchanged, the voltage drops, resulting in a decrease in output power, which easily leads to a decrease in power conversion efficiency. Utility Model Content

[0004] The purpose of the utility model is to provide a DC conversion circuit to solve the following technical problems:

[0005] How to provide a DC conversion circuit capable of high power conversion efficiency.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] A direct current conversion circuit, comprising:

[0008] An input filter module is connected to the peripheral DC voltage source voltage and filters the voltage input of the DC voltage source voltage to obtain a filtered voltage;

[0009] A communication circuit module, connected to the peripheral control output terminal and the isolated BOOST module, for providing a control signal to the isolated BOOST module;

[0010] The isolation BOOST module is connected to the input filter module and is used to boost the filter voltage according to the control signal to obtain a DC voltage;

[0011] An output filter module, connected to the isolation BOOST module, for filtering the DC voltage to obtain an output DC voltage;

[0012] The isolated BOOST module includes two isolated BOOST modules; one of the isolated BOOST modules includes a control module and a power main circuit module;

[0013] The control module controls the operation of the power main circuit module according to the control signal.

[0014] As a further solution of the utility model: the power main circuit module includes a chopper boost rectifier circuit and a drive control circuit:

[0015] The chopper boost rectifier circuit includes MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, resistor R14, resistor R15, resistor R18, resistor R19, resistor R23, transformer T1, capacitor C5, capacitor C6, capacitor C7, capacitor C8, capacitor C9, capacitor C10, capacitor C13, capacitor C14, diode D2, diode D3, diode D8, diode D9;

[0016] The drive control circuit includes a control chip U1, a control chip U5, a control chip U9, a control chip U12, a capacitor C2, a capacitor C3, a capacitor C17, a capacitor C31, a capacitor C32, a capacitor C39, a diode D4, a diode D6, a diode D7, a diode D10, a diode D11, a diode D13, a diode D14, a diode D15, a diode D15, a diode D17, a diode D20, a diode D21, a transformer CT1, a transformer CT2, a resistor R8, a resistor R9, a resistor R16, a resistor R17, a resistor R38, a resistor R39, a resistor R44, and a resistor R45.

[0017] As a further solution of the utility model: the control module includes a main control circuit, a voltage feedback circuit, a current acquisition circuit and a peak current module.

[0018] As a further solution of the utility model: the main control circuit includes a control chip U10, a capacitor C20, a capacitor C21, a capacitor C23, a capacitor C25, a capacitor C26, a capacitor C29, a resistor R21, a resistor R29, a resistor R31, a resistor R32, a resistor R33, a resistor R37 and a resistor R40.

[0019] As a further solution of the utility model: the voltage feedback circuit includes a signal isolator U11, a resistor R43, a resistor R46, a resistor R47, a resistor R48, a resistor R51, a resistor R52, a resistor R61, a capacitor C38, a capacitor C40, a capacitor C41 and a capacitor C42.

[0020] As a further solution of the utility model: the current acquisition circuit includes a resistor R68, a resistor R69, a resistor R72, a resistor R75, a resistor R76, a capacitor C47, a capacitor C53, a diode D24 and an amplifier U16.

[0021] As a further solution of the utility model: the peak current module includes capacitor C52, capacitor C54, capacitor C55, capacitor C56 and chip DM1.

[0022] Beneficial effects of the utility model: the DC conversion circuit of the utility model adopts a parallel-in-serial-out architecture, with two isolated BOOST modules inside, each outputting a voltage of V and a power of W. After the two modules are connected in series, the output voltage is 2V and the power is 2W. The control module and the power main circuit module can be independent of each other, thereby ensuring the power conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described below in conjunction with the accompanying drawings.

[0024] Figure 1 It is the principle block diagram of the DC conversion circuit in the utility model;

[0025] Figure 2 This is a schematic diagram of the power main circuit module circuit in the utility model;

[0026] Figure 3 This is a schematic diagram of the circuit structure of the main control circuit in the utility model;

[0027] Figure 4 It is a circuit structure diagram of the voltage feedback circuit in the utility model;

[0028] Figure 5 It is a structural schematic diagram of the current collection circuit in the utility model;

[0029] Figure 6 It is a structural schematic diagram of the peak current module in the utility model. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] See also Figure 1 As shown, the utility model is a DC conversion circuit, comprising:

[0032] An input filter module is connected to the peripheral DC voltage source voltage and filters the voltage input of the DC voltage source voltage to obtain a filtered voltage;

[0033] A communication circuit module, connected to the peripheral control output terminal and the isolated BOOST module, for providing a control signal to the isolated BOOST module;

[0034] The isolation BOOST module is connected to the input filter module and is used to boost the filter voltage according to the control signal to obtain a DC voltage;

[0035] An output filter module, connected to the isolation BOOST module, for filtering the DC voltage to obtain an output DC voltage;

[0036] The isolated BOOST module includes two isolated BOOST modules; one of the isolated BOOST modules includes a control module and a power main circuit module;

[0037] The control module controls the operation of the power main circuit module according to the control signal.

[0038] The DC conversion circuit in this embodiment of the utility model adopts a parallel-in-serial-out architecture, with two isolated BOOST modules inside, each outputting 135V and 1600W. After the two are connected in series, the output is 270V and the power is 3200W. The control module and the main power circuit module can be independent of each other, thereby ensuring the power conversion efficiency. The input filter module and the output filter module are both passive filter circuits composed of inductors and capacitors.

[0039] like Figure 2 and Figure 3 As shown, the power main circuit module includes a chopper boost rectifier circuit and a drive control circuit:

[0040] The chopper boost rectifier circuit includes MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, resistor R14, resistor R15, resistor R18, resistor R19, resistor R23, transformer T1, capacitor C5, capacitor C6, capacitor C7, capacitor C8, capacitor C9, capacitor C10, capacitor C13, capacitor C14, diode D2, diode D3, diode D8, diode D9;

[0041] The drive control circuit includes a control chip U1, a control chip U5, a control chip U9, a control chip U12, a capacitor C2, a capacitor C3, a capacitor C17, a capacitor C31, a capacitor C32, a capacitor C39, a diode D4, a diode D6, a diode D7, a diode D10, a diode D11, a diode D13, a diode D14, a diode D15, a diode D15, a diode D17, a diode D20, a diode D21, a transformer CT1, a transformer CT2, a resistor R8, a resistor R9, a resistor R16, a resistor R17, a resistor R38, a resistor R39, a resistor R44, and a resistor R45.

[0042] In this embodiment, if Figure 2 As shown, the voltage of the peripheral DC voltage source is DC 28V, which is converted into AC 28V through a chopper positive voltage rectifier circuit, the voltage is increased to AC 135V, and finally the AC 135V is rectified and output as DC 135V.

[0043] The DC conversion circuit in the utility model can be used in the operation of a hydraulic auxiliary pump in the field of refrigeration technology. After the DC conversion circuit receives the hydraulic auxiliary pump working signal, it can cut off the high-level output to the chopper boost rectifier circuit, turn off the MOS tube Q1, MOS tube Q2, MOS tube Q3 and MOS tube Q4, thereby cutting off the output of the DC conversion box and powering off the compressor assembly. The response time of this process is within 5ms, which is very fast.

[0044] Specifically, when the power main circuit module is working, the DC 28V is first chopped into 28V pulse AC by MOS tubes Q1, MOS tubes Q2, MOS tubes Q3 and MOS tubes Q4, and the 28V pulse AC is then boosted and rectified by transformer T1 to become a relatively stable DC 135V DC output.

[0045] The control module includes a main control circuit, a voltage feedback circuit, a current acquisition circuit and a peak current module.

[0046] like Figure 3 As shown, the main control circuit includes a control chip U10, a capacitor C20, a capacitor C21, a capacitor C23, a capacitor C25, a capacitor C26, a capacitor C29, a resistor R21, a resistor R29, a resistor R31, a resistor R32, a resistor R33, a resistor R37 and a resistor R40.

[0047] like Figure 4 As shown, the voltage feedback circuit includes a signal isolator U11, a resistor R43, a resistor R46, a resistor R47, a resistor R48, a resistor R51, a resistor R52, a resistor R61, a capacitor C38, a capacitor C40, a capacitor C41 and a capacitor C42.

[0048] like Figure 5As shown, the current acquisition circuit includes a resistor R68, a resistor R69, a resistor R72, a resistor R75, a resistor R76, a capacitor C47, a capacitor C53, a diode D24 and an amplifier U16.

[0049] like Figure 6 As shown, the peak current module includes capacitor C52, capacitor C54, capacitor C55, capacitor C56 and chip DM1.

[0050] like Figure 3 As shown, the control chip U10 uses the chip JUCC1895L. The main control circuit mainly receives voltage signals and current signals, etc., and sends control instructions to the drive control circuit and other circuits according to the received signals. The voltage feedback circuit collects the output voltage and monitors the output voltage. In order to ensure the high reliability and stability of the collection, the reference voltage 2.5V of the controllable precision voltage regulator TL431 is used for comparison, and the differential circuit is used for proportional amplification to ensure that the voltage collection is accurate and reliable. The signal is isolated through TP521 as the signal isolator U11, and the result is sent to the control chip U10; the current collection circuit is responsible for converting the current into a voltage signal, and using the operational amplifier to send its voltage value to the control chip U10 to realize the current sampling function; when the peak current module is working, it enters the peak current mode and outputs full power.

[0051] In summary, the control module includes the chip JUCC1895L (set in the main control circuit), the voltage feedback circuit and the current sampling circuit 5 and the peak current module. The feedback voltage can be differentially and proportionally amplified with the reference 2.5V by the controllable precision voltage regulator TL431, and then enter the chip JUCC1895L through the optocoupler isolation. The current signal enters the control chip after being amplified by the operational amplifier. The control loop is in peak current mode for full power output.

[0052] The above is a detailed description of an embodiment of the utility model, but the content is only a preferred embodiment of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. A DC conversion circuit, characterized in that: include: An input filter module is connected to the peripheral DC voltage source voltage and filters the voltage input of the DC voltage source voltage to obtain a filtered voltage; A communication circuit module, connected to the peripheral control output terminal and the isolated BOOST module, for providing a control signal to the isolated BOOST module; The isolation BOOST module is connected to the input filter module and is used to boost the filter voltage according to the control signal to obtain a DC voltage; An output filter module, connected to the isolation BOOST module, for filtering the DC voltage to obtain an output DC voltage; The isolated BOOST module includes two isolated BOOST modules; one of the isolated BOOST modules includes a control module and a power main circuit module; The control module controls the operation of the power main circuit module according to the control signal; The control module includes a main control circuit and a voltage feedback circuit, a current collection circuit and a peak current module coupled to the main control circuit; The power main circuit module includes a chopper boost rectifier circuit and a drive control circuit: The chopper boost rectifier circuit includes MOS tube Q1, MOS tube Q2, MOS tube Q5, MOS tube Q4, resistor R14, resistor R15, resistor R18, resistor R19, resistor R23, transformer T1, capacitor C5, capacitor C6, capacitor C7, capacitor C8, capacitor C9, capacitor C10, inductor L1, capacitor C13, capacitor C14, diode D2, diode D3, diode D8, diode D9; The drive control circuit includes a control chip U1, a control chip U5, a control chip U9, a control chip U12, a capacitor C2, a capacitor C3, a capacitor C17, a capacitor C31, a capacitor C32, a capacitor C39, a diode D4, a diode D6, a diode D7, a diode D10, a diode D11, a diode D13, a diode D14, a diode D15, a diode D15, a diode D17, a diode D20, a diode D21, a transformer CT1, a transformer CT2, a resistor R8, a resistor R9, a resistor R16, a resistor R17, a resistor R38, a resistor R39, a resistor R44, and a resistor R45; Among them, one end of the inductor L1 is connected to the 28V voltage and one end of the capacitor C13, the other end of the inductor L1 is connected to the drain of the MOS tube Q1, the gate of the MOS tube Q1 is connected to the resistor R14 and one end of the resistor R9, the drain of the MOS tube Q1 is connected to the drain of the MOS tube Q2, the other end of the resistor R14 is connected to the drain of the MOS tube Q4, the source of the MOS tube Q1 and one end of the primary winding of the transformer T1, the gate of the MOS tube Q4 is connected to the resistor R17 and one end of the resistor R18, the other end of the resistor R18 is connected to the resistor R23 and the input end of the current acquisition circuit, the other end of the resistor R23 is connected to the other end of the capacitor C13 and then grounded, and the MOS tube Q4 The source of the MOS transistor Q5 is connected to the source of the MOS transistor Q5 and one end of the resistor R19, the other end of the resistor R19 is connected to the gate of the MOS transistor Q5, the drain of the MOS transistor Q5 is connected to the source of the MOS transistor Q2, one end of the resistor R15 and the other end of the primary winding of the transformer T1, the capacitor C14 is connected in parallel with the capacitor C13, the anode of the diode D2 is connected to the cathode of the diode D8 and then connected to one end of the secondary winding of the transformer T1, the anode of the diode D3 is connected to the cathode of the diode D9 and then connected to the other end of the secondary winding of the transformer T1, the capacitor C10, the capacitor C5, the capacitor C6, the capacitor C7, the capacitor C8 and the capacitor C9 are respectively connected in parallel to the two ends of the secondary winding of the transformer T1; The anode of the diode D4 is connected to the cathode of the diode D7 and then coupled to the main control circuit through the control chip U1. One end of the capacitor C3 is connected to the cathode of the diode D7, and the other end is connected to one end of the primary winding of the transformer CT1. The other end of the primary winding of the transformer CT1 is connected to the connection point between the anode of the diode D11 and the cathode of the diode D13 and then coupled to the main control circuit through the control chip U5. The cathode of the diode D4 is connected to a 12V voltage and then connected to one end of the capacitor C13. The other end of the capacitor C13 is connected to the anode of the diode D7 and then grounded. The cathode of the diode D11 is connected to a 12V voltage and then connected to one end of the capacitor C17. end is connected, the other end of the capacitor C17 is connected to the anode of the diode D13 and then grounded; the other end of the resistor R9 is connected to one end of the resistor R8 and the anode of the diode D6, the other end of the resistor R8 and the cathode of the diode D6 are connected to one end of the first secondary winding of the transformer CT1, the other end of the first secondary winding of the transformer CT1 is connected to the drain of the MOS tube Q4, the other end of the resistor R17 is connected to one end of the resistor R16 and the anode of the diode D10, the other end of the resistor R16 and the cathode of the diode D10 are connected to one end of the second secondary winding of the transformer CT1, and the other end of the second secondary winding of the transformer CT1 is grounded; The anode of the diode D14 is connected to the cathode of the diode D16 and then coupled to the main control circuit through the control chip U9. One end of the capacitor C32 is connected to the cathode of the diode D16, and the other end is connected to one end of the primary winding of the transformer CT2. The other end of the primary winding of the transformer CT2 is connected to the connection point between the anode of the diode D20 and the cathode of the diode D21 and then coupled to the main control circuit through the control chip U9. The cathode of the diode D14 is connected to a 12V voltage and then connected to one end of the capacitor C31. The other end of the capacitor C31 is connected to the anode of the diode D16 and then grounded. The cathode of the diode D20 is connected to a 12V voltage and then connected to the cathode of the capacitor C39. One end of the capacitor C39 is connected to the anode of the diode D21 and then grounded; the other end of the resistor R39 is connected to one end of the resistor R38 and the anode of the diode D15, the other end of the resistor R38 and the cathode of the diode D15 are connected to one end of the first secondary winding of the transformer CT2, the other end of the first secondary winding of the transformer CT2 is connected to the drain of the MOS tube Q5, the other end of the resistor R45 is connected to one end of the resistor R44 and the anode of the diode D17, the other end of the resistor R44 and the cathode of the diode D17 are connected to one end of the second secondary winding of the transformer CT2, and the other end of the second secondary winding of the transformer CT2 is grounded.

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